Various examples of decorative surfaces are known, in particular from the automotive coating industry, for example, individual coats, such as special effect coats, coats in special colors or coats in the form of pictures, patterns or ornaments, but also the application of correspondingly designed adhesive film. Various types of pigment may be used for coats of this type, for example, simple color pigments, mica pigments, special effect pigments.
Novel pigments have been found which resemble naturally occurring opals and wherein the color activity is produced by Bragg scattering of the incident light on the grid planes of the spheres arranged in a crystal-like manner.
WO 01/88044 describes pigments with an opalescent effect. The pigment particles consist of monodisperse spheres in a three-dimensional, tightly packed and regularly arranged structure, also called three-dimensional photonic crystals, with a diameter of 50 nm to 2 μm. The method for producing these particles may be used to coat substrate surfaces in that the monodisperse spheres are applied in suspension to the substrate surface and the liquid medium is removed.
WO 02/44301 describes similar pigments with an opalescent effect, of which the structure is formed by arrangement of monodisperse spheres and retention of smaller particles in the cavities between the monodisperse spheres.
EP-A 955 323 describes core/shell particles which may be used as special effect pigments to produce coatings, paints and inks. With respect to their cores, the particles may have a regular arrangement and are based substantially on high molecular polymers. They may be applied to the substrates in the form of solid, liquid or paste preparations with the aid of auxiliary constituents and additives.